MRI: Acquisition of an All Digital Multiparameter Gamma Spectroscopy System for Research and Research Training in Nuclear Physics

弱相互作用是自然界四种基本力之一，它是一种被称为衰变的放射性衰变的原因。对β衰变的精确测量可以探测我们对弱相互作用的理解的极限，在寻找新物理学的粒子对撞机实验中补充，同时成本要低得多。最近，国家超导回旋加速器实验室（National Superconducting Cyclotron Laboratory）等设施的发展，可以产生各种放射性同位素束，这为改进β衰变测量创造了新的机会。为了充分利用这些新同位素的潜力，需要对各种类型的粒子探测器的响应有很好的了解。了解粒子探测器的反应对于国土安全、核保障和医学的许多应用也很重要。通过这笔拨款获得的仪器将能够在广泛的能量范围内将各种粒子探测器的响应测量精度提高到一个新的水平。对核衰变中光谱形状的精确测量对粒子相互作用标准模型之外的物理现象很敏感。最近强大的放射性束流设备的发展创造了一个新的机会，通过在完全包含发射粒子的探测器中植入原子核来改进核谱形状的测量。在理想情况下，这提供了没有许多系统e&amp；#64256；更传统的β光谱学受到的影响。然而，要充分利用新探测器方法的潜力，需要对植入探测器的响应有精确的了解。该探测器的响应特性是通过提议的全数字多参数伽马光谱系统实现的主要研究。表征的基础是广角康普顿重合技术。该技术使用康普顿散射和中等强度的标准伽玛源来表征任何探测器材料的能量依赖电子响应，例如，高纯度锗探测器。根据这项建议获得的系统将使各种探测器的非线性测量达到新的精度水平，并在比目前存在的更宽的能量范围内进行测量。

The weak interaction, one of the four fundamental forces of nature, is responsible for the type of radioactive decay called beta decay. Precise measurements of beta decay can probe the limits of our understanding of the weak interaction, complementing particle collider experiments in the search for new physics while being much less costly. The recent development of facilities, such as at the National Superconducting Cyclotron Laboratory, that can produce a variety of beams of radioactive isotopes has created new opportunities for improved beta decay measurements. To fully exploit the potential of these new isotopes requires a good understanding of the response of various types of particle detectors. Understanding the response of particle detectors is also important for many applications in homeland security, nuclear safeguards, and medicine. The instrument to be acquired through this grant will enable the measurement of the response of a variety of particle detectors to a new level of precision over a wide energy range. Precise measurements of the shapes of spectra in nuclear beta decay are sensitive to physics beyond the Standard Model of particle interactions. The recent development of powerful radioactive beam facilities has created a new opportunity for improved measurements of nuclear beta spectrum shapes through implantation of the nuclei in detectors that fully contain the emitted particles. In the ideal case, this provides measurements free of many of the systematic effects more conventional beta spectroscopy is subject to. Fully exploiting the potential of the new detector method, however, requires precise knowledge of implantation detector response. This detector response characterization is the primary research to be enabled by the proposed acquisition of an all-digital multi-parameter gamma spectroscopy system. The basis of the characterizations is the Wide Angle Compton Coincidence technique. This technique uses Compton scattering with standard gamma sources of modest strength to characterize the energy dependent electron response of essentially any detector material relative to, for example, a High Purity Germanium detector. The system acquired under this proposal will enable the measurement of the nonlinearity of a wide variety of detectors to a new level of precision and over a wider energy range than presently exists.